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Wednesday, September 17, 2014

The 3 Types of VoIP Lines for Business

By: John Shepler

Businesses large and small have been migrating to VoIP telephone technology for years now. Some are delighted with the move and have never look back. Others feel like they’ve lost something in the way of performance. The calls are often muddled and it’s hard to carry on a two way conversation. Would you believe that its the exact same technology involved? Why is it that VoIP telephony can range from excellent to unacceptable? Let’s take a look.

What’s VoIP
VoIP or Voice over Internet Protocol is a means to convert telephones into computer peripherals. The reason to do that is both to save money and enable applications that just won’t work on the old style telephone network. Network voice is a powerful tool, but can more easily be degraded that simpler analog phones.

Old School Phone Systems
Business phone lines are sometimes called POTS for Plain Old Telephone Service. They consist of twisted copper pair wires that run directly from the phone set all the way to the telephone company. Each phone has its own set of wires. Once you get more than a few phones, however, you face a mounting phone bill since the telco charges you to make internal as well as external calls.

Companies get around this by installing their own phone switches. Small systems use Key Telephone Systems where multiple outside lines are available on each phone but you can also call within the building on your own wiring. Larger companies install PBX (Private Branch Exchange) switches that manage a pool of outside lines that can be assigned to any phone as needed.

If you only have a couple of phones, each with their own line, the phone company takes care of all the switching for you. With many phones, you become your own little phone company for inside calls. That means you have to take care of all the special phone wiring and the Key or PBX switching equipment. Plus, you have to pay for multiple outside analog lines or a digital PRI trunk to get to the public telephone system.

How VoIP is Different
With VoIP, each phone plugs into your company LAN. That gets rid of the second special phone network. You still need something to switch the calls between phones. This can be a VoIP PBX or IP PBX that you have in-house. It can also be a much larger hosted PBX system from a hosted VoIP service provider. Hosted means that a specialized company “hosts” or run the system. You are one of many clients that they host. It’s pretty much like buying web hosting. You simply pay by the month for service instead of having to install and maintain your own equipment.

VoIP Phone Line Needs
All VoIP phones connect to a local network. This can be a small home office network that has only a computer, WiFi router, VoIP phone adaptor (for a regular phone) and broadband modem. Or, it can be an extensive corporate LAN that is bridged into multiple business locations nationwide and even overseas. The principles and the requirements for high quality performance are the same.

Since the network is shared with many phones and other computing devices, it take some doing to make sure that you get high performance. With dedicated analog lines, that’s the phone company’s problem. With VoIP, it’s now your IT problem.

What’s needed is plenty of bandwidth to accommodate all the phones and other devices. But that’s not enough. You need to give the voice packets priority over data because phone calls will start sounding muddled and choppy long before you notice that the file is loading slower. The network also needs low latency, packet loss and jitter to be transparent to the packets carrying the VoIP digitized phone conversations.

Using the Internet as Your Phone LIne
The low end of the market, which keeps costs low for home offices and small businesses, uses a broadband Internet service to connect to the VoIP service provider. You can share your broadband connection with a couple of computers, a WiFi router, and a few VoIP phones. You’ll need a router that creates CoS (Class of Service) to prioritize the phones or the computers will interfere with your calls. Sometimes the service provider will give you an adaptor that does this.

The advantage of using the Internet as a phone line is that it’s cheap. You probably already have broadband for your computer. The lure is to save money by “eliminating the separate phone line.” The downside is that the Internet was never designed for telephony. It was intended to reliably transport data files. There is no prioritization of voice on the Internet and most access lines, like DSL, Cable, Satellite and Cellular, are shared broadband. It’s a cost vs performance tradeoff. You may find that some calls sound perfect but others break up or sound muddled. It all depends on what else is happening on the Internet while you are making your call.

One way to improve Internet VoIP is to use a dedicated Internet access (DIA) like T1 or Ethernet over Copper. This keeps your neighbors from disrupting your calls while they download large video and software programs, but you are still subject to network congestion on the Internet itself.

Private Line VoIP Service
Companies that depend on high quality phone service for customer support and employee productivity usually sidestep the Internet in favor of something more predictable. The outside line that compares most closely to the legacy analog and PRI lines is the SIP Trunk. This is a digital broadband line, but it is a private line that is not shared with others. It’s called a SIP trunk because it supports SIP or Session Initiation Protocol, the switching system for VoIP calls.

A simple SIP trunk is a T1 line that runs from your network to your service provider. It supports up to a couple dozen simultaneous phone conversations or a combination of phone calls and Internet. The Internet service has a lower priority than the phone calls and uses whatever bandwidth isn’t needed for the phones at any given time. Smaller companies that don’t have dozens of phones find this is a great cost saver compared to maintaining separate phone and broadband lines.

Larger SIP trunks are also available for bigger companies or call centers. Both copper and fiber optic bandwidth is available to support as many calls as you need.

Voice over MPLS Networks
Major corporations generally have many business sites located around the country and even in other countries. They still want any employee to easily call any other employee without paying long distance toll charges. They also need to make outside calls to anyone with a phone.

A sophisticated solution is called VoMPLS or Voice over MPLS networks. MPLS is a private network arrangement with a regional, national or international service footprint. The network operator ensures that each paying customer has the necessary Class of Service, bandwidth and low latency, packet loss and jitter that they need for high performance.

VoMPLS works a lot like VoIP using SIP Trunks. The difference is that instead of having to run dedicated private lines among all your locations, you simply need an access line from each location to the MPLS network. This can give you a major cost savings, especially on those long international connections, while maintaining high network performance.

Are you in search of a better telephone solution, to reduce costs, increase available features or both? If so, there are VoIP telephone solutions you should take a close look at.

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Telexplainer Google+ is a service of T1 Rex and was formerly known as "T1 Rex's Business Telecom Explainer." Our mission is to offer technical and business information related to telecommunications and computer networking. We are teamed with Telarus, Inc. as our broker for worldwide telecom services, and are affiliates of other commercial services. Many images are used under license from Animation Factory or courtesy of Wikimedia Commons. Some are available on products from the Gigapacket Tech Store on Zazzle. Written and published by John Shepler. Profile+ You may contact me by sending email to: John (at) Telexplainer.com View John Shepler's profile